[Vee]

I have a 2000 Taurus SE-S with the Duratec. I have no mods to it, other than an aftermarket radio which was installed years ago.

I have one dim headlight. Its the passenger side light.

I bought new bulbs. No difference.

I cleaned out the connectors using electrical contact cleaner. No difference.

I swapped bulbs. The passenger side still didn't light up, so it's not the bulb.

I googled around and noted two possibilities:

1. Bad ground. Now I did a visual all over the car, and it looks like the grounds are...above average for a 10 year old car. No crusting anywhere.

2. Harness connector may need to be replaced. There is one tooth divided in two that keeps the bulb plugged in. One of the two halves of this tooth has broken off, but that may have happened when I was replacing the bulbs last night. (It was dark) Should I splice in a new harness? I can't imagine it would take too long, and they're cheap.

Is there some type of historical indicator on what my problem could be? I did a search on "dim headlight", but this site kept ignoring dim so I end up with every headlight post possible.

Thanks for any help.

 

[izzmo]

Best thing to do is get a multimeter (or voltmeter or ampmeter) and test the voltage and current through the light.

 

[KhanTyranitar]

If you get a headlight relay harness, not only would it fix your problem, it will actually make the headlights slightly brighter.

 

[goodbrosuit]

check the resistance in the wires before replacing anything. find the wire that has the high resistance first, don't waste money

 

[izzmo]

It's probably something with a bad ground or something with your MFS.

But... a headlight harness would definitly do the trick.

 

[FL_Gal]

check your fuses.

I dontk now if your car may have it, but I've had cars before where there's a fuse for each headlight, and if the fuse is blown, it will look dim.

 

[ludacris]

x2 on checking resistance and grounds. Bad grounds will mess with your head. Keep it clean and tight!

 

[soundu]

On my old 93 , i had a weak light issue. turned out, water had gotten into the reflector
and caused the silver on the back of the reflector to flake off. The bulb was OK, but there was almost NO reflective surface so the light output was weak.

 

[danhasenauer]

Read the voltage at the connector on the dim side. You will probably find it to be less than 12v. I suspect a cruddy ground connection on that side.

 

[Multi Taurus]

Thanks all. Am sure I have a ground issue but am stuck. I ran a separate ground wire that corrects the issue. Unfortunately the lights stay permanently on with the extra ground wire... Anybody know where the drivers headlight is grounded? I found and cleaned 5 different under-hood grounds (engine block, battery cable, drivers side inner fender near battery ground, passenger side inner fender, stud near fuel rail). I have also checked the headlight connector and both sides of the connector upstream for corrosion but cant find any corrosion. Thanks for advising me on the next thing to try.

 

[soundu]

Thanks all. Am sure I have a ground issue but am stuck. I ran a separate ground wire that corrects the issue. Unfortunately the lights stay permanently on with the extra ground wire... Anybody know where the drivers headlight is grounded? I found and cleaned 5 different under-hood grounds (engine block, battery cable, drivers side inner fender near battery ground, passenger side inner fender, stud near fuel rail). I have also checked the headlight connector and both sides of the connector upstream for corrosion but cant find any corrosion. Thanks for advising me on the next thing to try.

Here is what it looks like electrically:

http://www.justanswer.com/uploads/wmarti7/2009-07-08_003205_2000_taurus.gif

If you know how to read schematics, you will note the ground is switched
and NOT the hot. Thats why the light is fine when you hook up ground wire
to it. Also note the path is though the muti function switch as well as
the headlight switch.

Your going to have some fun under the dash with your DVM to find out
where you high resistance contact is. It could be either switch, or
in any connector in-between.

I would start with the two connectors before the MFS, C202 and C264.
inspect them close for burn marks or overheating.
(hopefully, I gave your the correct reference numbers)